U.S. patent application number 10/608201 was filed with the patent office on 2004-01-01 for photovoltaic tiles, roofing system, and method of constructing roof.
This patent application is currently assigned to AstroPower, Inc.. Invention is credited to Ressler, Stephen.
Application Number | 20040000334 10/608201 |
Document ID | / |
Family ID | 29782677 |
Filed Date | 2004-01-01 |
United States Patent
Application |
20040000334 |
Kind Code |
A1 |
Ressler, Stephen |
January 1, 2004 |
Photovoltaic tiles, roofing system, and method of constructing
roof
Abstract
There are provided photovoltaic tiles (each containing at least
one photovoltaic cell) which can be readily integrated into a roof
structure constructed of standard roofing materials. The
photovoltaic tiles have frames which hold photovoltaic elements,
the frames having end portions which are engageable with opposite
end portions of similarly-shaped photovoltaic tiles and/or with end
portions of standard roofing tiles, and/or which are shaped similar
to shapes of end portions of standard roofing tiles. There are also
provided roofing systems including standard roofing tiles and such
photovoltaic tiles. There are also provided methods of constructing
a roof using such a roofing system.
Inventors: |
Ressler, Stephen;
(Wilmington, DE) |
Correspondence
Address: |
BURR & BROWN
PO BOX 7068
SYRACUSE
NY
13261-7068
US
|
Assignee: |
AstroPower, Inc.
Newark
DE
|
Family ID: |
29782677 |
Appl. No.: |
10/608201 |
Filed: |
June 27, 2003 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
60392341 |
Jun 27, 2002 |
|
|
|
Current U.S.
Class: |
136/251 ;
52/173.3 |
Current CPC
Class: |
E04D 2001/308 20130101;
Y02E 10/50 20130101; Y02B 10/20 20130101; E04D 2001/3458 20130101;
F24S 25/20 20180501; E04D 1/2916 20190801; F24S 2025/6002 20180501;
H02S 20/23 20141201; Y02B 10/10 20130101; Y02E 10/47 20130101; E04D
2001/3414 20130101; H02S 20/25 20141201 |
Class at
Publication: |
136/251 ;
52/173.3 |
International
Class: |
H01L 025/00 |
Claims
1. A photovoltaic tile, comprising: at least one photovoltaic
element having at least one photovoltaic collection surface; and a
frame holding said at least one photovoltaic element such that said
at least one photovoltaic element is substantially held in place
relative to said frame, said frame comprising a first end portion
and a second end portion, said first end portion being of a shape
which is engageable with a shape of said second end portion.
2. A photovoltaic tile as recited in claim 1, wherein said frame
comprises a front frame surface and a back frame surface, said
front frame surface and said back frame surface each having a
length which is a multiple of a length of a standard roofing
tile.
3. A photovoltaic tile as recited in claim 1, wherein said first
end portion comprises an upward hook shape, and said second end
portion comprises a downward hook shape.
4. A photovoltaic tile, comprising: at least one photovoltaic
element having at least one photovoltaic collection surface; and a
frame holding said at least one photovoltaic element such that said
at least one photovoltaic element is substantially held in place
relative to said frame, said frame comprising a first end portion
having a shape which is engageable with at least a first side
portion of a standard roofing tile.
5. A photovoltaic tile as recited in claim 4, wherein said frame
further comprises a second end portion having a shape which is
engageable with a shape of said first end portion.
6. A photovoltaic tile as recited in claim 4, wherein said frame
further comprises a second end portion having a shape which is
engageable with a second side portion of said standard roofing
tile.
7. A photovoltaic tile as recited in claim 4, wherein said frame
comprises a front frame surface and a back frame surface, said
front frame surface and said back frame surface each having a
length which is a multiple of a length of said standard roofing
tile.
8. A photovoltaic tile, comprising: at least one photovoltaic
element having at least one photovoltaic collection surface; and a
frame holding said at least one photovoltaic element such that said
at least one photovoltaic element is substantially held in place
relative to said frame, said frame comprising a first end portion
having a shape which is similar to at least a shape of a first side
portion of a standard roofing tile.
9. A photovoltaic tile as recited in claim 8, wherein said frame
further comprises a second end portion having a shape which is
similar to a shape of a second side portion of said standard
roofing tile.
10. A photovoltaic tile as recited in claim 8, wherein said frame
comprises a front frame surface and a back frame surface, said
front frame surface and said back frame surface each having a
length which is a multiple of a length of a standard roofing
tile.
11. A roofing system, comprising: at least one photovoltaic tile as
recited in claim 6, said photovoltaic tile further comprising at
least one underhang portion attached to or integral with said
frame; and at least one retaining clip, said retaining clip
comprising an underhang engaging portion having a thickness which
is smaller than a thickness of a space between said underhang
portion and said frame.
12. A roofing system as recited in claim 11, wherein said retaining
clip has a first substantially flat portion for engagement with a
roof deck, an underhang engaging portion for fitting between said
underhang portion and said frame, and a third portion connecting
said first portion to said underhang engaging portion.
13. A roofing system, comprising: a plurality of roofing tiles,
each said roofing tile having a first side portion and a second
side portion; and at least one photovoltaic tile as recited in
claim 6.
14. A roofing system, comprising: at least one photovoltaic tile as
recited in claim 9, said photovoltaic tile further comprising at
least one underhang portion attached to or integral with said
frame; and at least one retaining clip, said retaining clip
comprising an underhang engaging portion having a thickness which
is smaller than a thickness of a space between said underhang
portion and said frame.
15. A roofing system as recited in claim 14, wherein said retaining
clip has a first substantially flat portion for engagement with a
roof deck, said underhang engaging portion for fitting between said
underhang portion and said frame, and a third portion connecting
said first portion to said underhang engaging portion.
16. A roofing system, comprising: a plurality of roofing tiles,
each said roofing tile having a first side portion and a second
side portion; and at least one photovoltaic tile as recited in
claim 9.
17. A method of constructing a roof, comprising: positioning at
least one roofing tile on a roof surface, said at least one roofing
tile having a first side portion; and positioning at least a first
photovoltaic tile on said roof surface, said first photovoltaic
tile comprising a first photovoltaic element and a first frame,
said first frame holding said first photovoltaic element such that
said first photovoltaic element is substantially held in place
relative to said first frame, said first frame comprising a first
end portion, such that said first end portion of said first frame
is engaged with said first side portion of said at least one
roofing tile.
18. A method as recited in claim 17, further comprising attaching
at least one retaining clip to said roof deck, said frame having an
underhang portion attached thereto, and while positioning said at
least one photovoltaic tile on said roof surface, a free end of
said retaining clip slides between said frame and said underhang
portion.
19. A method as recited in claim 18, wherein an underhang engaging
portion of said retaining clip overlaps only a portion of said
underhang portion, whereby a first photovoltaic tile in one course
can be mounted on said roof surface above a second photovoltaic
tile in a different course such that a desired reveal length of
said second photovoltaic tile is not overlapped by said first
photovoltaic tile.
20. A method as recited in claim 17, further comprising:
positioning at least a second photovoltaic tile on said roof
surface, said second photovoltaic tile comprising at least a second
photovoltaic element and a second frame, said second frame holding
said second photovoltaic element such that said second photovoltaic
element is substantially held in place relative to said second
frame, said second frame comprising a second frame first end
portion and a second frame second end portion, such that said
second frame first end portion is engaged with a second end portion
of said first frame.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Patent Application No. 60/392,341, filed Jun. 27, 2002, the
entirety of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention is directed to photovoltaic tiles in
which each photovoltaic tile contains one or more photovoltaic
cells, and which can be integrated into a roof structure
constructed of standard roofing materials. The present invention is
further directed to a roofing system including standard roofing
tiles and one or more photovoltaic tiles of the present invention.
The present invention is also directed to a method of constructing
a roof using a roofing system according to the present
invention.
BACKGROUND OF THE INVENTION
[0003] Solar energy collection is of great importance and is of
ever-increasing importance, particularly in light of limitations
and environmental concerns associated with other sources of energy,
and the resulting ever-increasing demand for "alternative" energy
(i.e., non-fossil fuel energy).
[0004] Photovoltaic modules have been deployed in a wide variety of
ways, including deployment on the roofs of buildings, including
private homes. However, such panels have not been capable of being
readily integrated into roof structures constructed of standard
roofing materials, placing a limitation on the usage of
photovoltaic modules in a variety of locations where solar energy
could otherwise be collected. For example, many communities
prohibit the mounting of conventional photovoltaic modules on the
front roofs of homes because the conventional photovoltaic modules
cannot be effectively integrated into roof structures constructed
of standard roofing materials.
BRIEF SUMMARY OF THE INVENTION
[0005] In accordance with the present invention, there are provided
photovoltaic tiles (each containing at least one photovoltaic cell)
which can be readily integrated into a roof structure constructed
of standard roofing materials. The present invention is further
directed to a roofing system including standard roofing tiles and
one or more photovoltaic tiles of the present invention. The
present invention is also directed to a method of constructing a
roof using a roofing system according to the present invention. The
present invention provides roofs in which photovoltaic tiles are
securely fastened to the roof, in which the photovoltaic tiles lay
close to the roof surface, and/or in which the photovoltaic tiles
provide a high degree of uniformity and similarity in dimension to
the roofing tiles. These structural features make it possible to
integrate the photovoltaic tiles of the present invention with
standard roofing tiles to provide an integrated structure which is
aesthetically improved compared to conventional photovoltaic
options.
[0006] According to the present invention, there is provided a
photovoltaic tile which has at least one end portion which is
engageable with an end portion of another similarly-shaped
photovoltaic tile and/or an end portion of a standard roofing
tile.
[0007] In one aspect of the present invention, there is provided a
photovoltaic tile which has first and second end portions which
have respective shapes which are substantially identical to the
shapes of first and second side portions of a standard roofing
tile, such first and second side portions being shaped such that a
first side portion of one of such standard roofing tiles is
engageable with a second side portion of a second such standard
roofing tile.
[0008] The present invention is directed to a photovoltaic tile,
comprising at least one photovoltaic element having at least one
photovoltaic collection surface; and a frame extending around an
edge of the photovoltaic element, the frame holding the
photovoltaic element in place relative to the frame.
[0009] In one aspect of the present invention, the frame comprises
a first end portion having a shape which is engageable with a shape
of the second end portion, such that a pair of photovoltaic
elements can be engaged with each other by engaging the first end
portion of one with the second end portion of the other.
[0010] In another aspect of the present invention, the frame
comprises a first end portion having a shape which is engageable
with at least a first side portion of a standard roofing tile.
Preferably, the frame further comprises a second end portion having
a shape which is engageable with a second side portion of the
standard roofing tile.
[0011] In a further aspect of the present invention, the frame
comprises a first end portion having a shape which is similar to at
least a first side portion of a standard roofing tile.
[0012] In addition, the present invention is directed to a roofing
system comprising a plurality of roofing tiles and at least one
photovoltaic tile as described above. The present invention is
further directed to a roofing system which further comprises a roof
deck on which the roofing tiles and the at least one photovoltaic
tile are mounted, and preferably also a support structure on which
the roof deck is supported.
[0013] The photovoltaic elements described above preferably each
comprise at least one photovoltaic cell mounted in a casing.
Preferably, the photovoltaic elements each have a dead space in
order to provide an overlap, e.g., an area where a portion of a
tile in a row (course) of tiles mounted lower on a roof is
overlapped by portions of tiles in a course mounted farther up the
roof.
[0014] In a preferred aspect of the present invention, the width of
the frame (i.e., the dimension in the direction in which the tiles
in a course are arranged) is a multiple of the width of the roofing
tile, so that each photovoltaic element can be mounted so as to
occupy an area where one or more roofing tiles would fit, thereby
providing the ability to provide continuity in an overall pattern
of a roof structure which includes roofing tiles and photovoltaic
tiles.
[0015] The present invention is further directed to a method of
constructing a roof, comprising positioning on a roof surface at
least one roofing tile having a first side portion and a second
side portion and at least one photovoltaic tile, such that a first
end portion of the frame of the photovoltaic tile is engaged with a
first side portion of the roofing tile.
[0016] The present invention is further directed to a method of
constructing a roof, comprising positioning on a roof surface at
least a first photovoltaic tile and a second photovoltaic tile,
such that a second end portion of the frame of the second
photovoltaic tile is engaged with a first end portion of the frame
of the first photovoltaic tile.
[0017] In addition, the present invention is directed to a method
of constructing a roof, comprising positioning on a roof surface a
plurality of roofing tiles and a plurality of photovoltaic tiles,
each of the roofing tiles having a first side portion and a second
side portion, each of the photovoltaic tiles comprising a frame
having a first end portion and a second end portion, such that each
first end portion is engaged with a second end portion of another
frame or with a second side portion of one of the roofing tiles,
and such that each second end portion is engaged with a first end
portion of another frame or a first side portion of one of the
roofing tiles.
[0018] The invention may be more fully understood with reference to
the accompanying drawings and the following description of the
embodiments shown in those drawings. The invention is not limited
to the exemplary embodiments and should be recognized as
contemplating all modifications within the skill of an ordinary
artisan.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0019] FIG. 1 is a schematic view of a preferred embodiment of the
top of a photovoltaic element which is suitable for use according
to the present invention.
[0020] FIG. 2 is a perspective view of an example of a standard
roofing tile.
[0021] FIG. 3 is a perspective view of a front end of a first
embodiment of a frame according to the present invention.
[0022] FIG. 4 is a perspective view of the back side of the front
frame member of FIG. 3.
[0023] FIG. 5 is a cross-sectional view of a left end portion of a
first photovoltaic tile, a roofing tile engaged with the first
photovoltaic tile, and a right end portion of a second roofing tile
engaged with the roofing tile, according to a second embodiment of
a frame according to the present invention.
[0024] FIG. 6 is a cross-sectional view of a front portion of a
frame of a photovoltaic tile according to the second
embodiment.
[0025] FIG. 7 is a cross-sectional view of a rear portion of a
frame of a photovoltaic tile according to the second
embodiment.
[0026] FIG. 8 is a cross-sectional view of a left end portion of a
first photovoltaic tile, a roofing tile engaged with the first
photovoltaic tile, and a right end portion of a second roofing tile
engaged with the roofing tile, according to a third embodiment of a
frame according to the present invention.
[0027] FIG. 9 is a cross-sectional view showing a roofing tile
applied to a roof in one course, a photovoltaic tile applied to the
roof in a next course, and a second photovoltaic tile applied to
the roof in a further course.
[0028] FIG. 10 is a perspective view depicting photovoltaic tiles
engaged with other photovoltaic tiles, photovoltaic tiles engaged
with roofing tiles, and a roofing tile engaged with another roofing
tile.
DETAILED DESCRIPTION OF THE INVENTION
[0029] As mentioned above, the present invention provides
photovoltaic tiles (each containing at least one photovoltaic cell)
which can be readily integrated into a roof structure constructed
of standard roofing materials.
[0030] The photovoltaic tiles according to the present invention
each include at least one photovoltaic element and a frame which
holds the photovoltaic element in place relative to the frame.
[0031] FIG. 1 depicts a preferred embodiment of a photovoltaic
element 10 which is suitable for use according to the present
invention. In the photovoltaic element 10 shown in FIG. 1, eighteen
photovoltaic cells 11 are encapsulated in a transparent casing 12,
preferably made of glass. The photovoltaic element 10 shown in FIG.
1 includes a dead space 13, where no photovoltaic cells or portions
of photovoltaic cells are present.
[0032] A variety of photovoltaic cells are known in the art, e.g.,
structures which can separate charges, such as p-i-n devices,
photo-electrochemical devices (e.g., Grtzel Cells, such as those
disclosed in U.S. Pat. Nos. 4,927,721 and 5,084,365, the entireties
of which are hereby incorporated by reference) and p/n junction
devices, as well as quantum dot devices which separate charges due
to differences in recombination rates between electrons and holes.
The invention is applicable to these and any other photovoltaic
cells.
[0033] In the case of p/n junction devices, as is well known, a
photovoltaic cell comprises at least one diode comprising at least
one n-type region and at least one p-type region. The ntype region
and the p-type region are in contact with each other, so as to form
a p-n junction. In order to maximize the surface area of solar
collection, photovoltaic cells typically have a substantially flat
surface which faces the source of light (e.g., the sun).
[0034] Typically, such photovoltaic elements further include n-type
region and p-type region contact layers, an antireflective,
substantially transparent coating over the n-region contact layer,
a transparent cover glass over the antireflective coating, a
junction box, and electrical lead lines (often referred to as
"pigtails"), all of which are well known in the art. The electrical
lead lines of a number of photovoltaic elements can be connected
(e.g., using "quick connectors") in series to combine the power
produced by such photovoltaic elements.
[0035] The photovoltaic element 10 depicted in FIG. 1 has a frame
which has a front edge 14, a left edge 15, a right edge 16
(opposite the left edge 15), a back edge 17 (opposite the front
edge 14), a photovoltaic collection surface (on the top, facing out
of the page) and a bottom surface (opposite the photovoltaic
collection surface). A junction box can be positioned at any
suitable location as is well known in the art, e.g., on the bottom
of the photovoltaic element.
[0036] The frame preferably extends around an edge of the at least
one photovoltaic element, and holds the at least one photovoltaic
element in place relative to the frame. In one aspect of the
present invention, the frame comprises a first end portion and a
second end portion, the first end portion having a shape which is
engageable with a shape of the second end portion, such that a pair
of such photovoltaic elements can be engaged with each other by
engaging the first end portion of one with the second end portion
of the other.
[0037] In another aspect of the present invention, the frame
comprises a first end portion having a shape which is engageable
with at least a first side portion of a standard roofing tile.
Preferably, the frame further comprises a second end portion having
a shape which is engageable with a second side portion of the
standard roofing tile.
[0038] In a further aspect of the present invention, the frame
comprises a first end portion having a shape which is similar to at
least a first side portion of a standard roofing tile. Preferably,
the frame further comprises a second end portion having a shape
which is similar to a second side portion of the standard roofing
tile.
[0039] The frame according to the present invention can be made of
any suitable material. For example, the frame is preferably made of
aluminum.
[0040] FIG. 2 depicts an example of a standard roofing tile 20,
made, e.g., of concrete. The tile 20 depicted in FIG. 2 has a right
side portion 21 and a left side portion 22. The right side portion
21 includes an overhang portion 23 and an overlay portion 24. The
left side portion 22 includes an upright portion 25 and a trough
portion 26. When installing such roofing tile, a first tile is
positioned on the roof with its top surface 27 away from the roof,
and then a second tile is positioned on the roof, also with its top
surface 27 away from the roof, such that the right side portion 21
of the second tile engages with the left side portion 22 of the
first tile, whereby the overlay portion 24 of the second tile is
adjacent to or in contact with the upright portion 25 of the first
tile, and the overhang portion 23 of the second tile is adjacent to
or in contact with the trough portion 26 of the first tile. In some
cases, each tile includes a bottom hanging portion (see reference
no. 29 in FIG. 9) which hangs over a batten (see reference nos. 96
in FIG. 9) which has been attached to the roof deck, in order to
assist in holding the tiles on the roof. In the tile 20 shown in
FIG. 2, there are further provided holes 28 through which screws,
nails, bolts or any other attachment element can be inserted and
driven into or otherwise engaged with the roof deck to assist in
holding the tiles on the roof. Furthermore, one or more retaining
clips (see reference nos. 90 and 97 in FIG. 9) can be attached to
the roof deck, the retaining clips including a portion which covers
a portion of the top surface 27 (preferably on the end remote from
where the holes 28 are shown), to assist in holding the tiles on
the roof (e.g., in high winds).
[0041] FIG. 3 depicts a front end of a first embodiment of a frame
according to the present invention, suitable for use in making
photovoltaic tiles which can be used, together with roofing tiles,
e.g., tiles 20 as shown in FIG. 2, in constructing a roof. The
frame includes a left end portion 31 and a right end portion 32.
FIG. 3 also shows top elements 33 of the frame and lower elements
34. The photovoltaic element (not shown in FIG. 3) is positioned
between the top elements 33 and the lower elements 34, the top
elements 33 and the lower elements 34 supporting the photovoltaic
element and serving to assist in holding the photovoltaic element
in place. The left end portion 31 includes an upright portion 35
and a trough portion 36. The right end portion 32 includes an
overhang portion 37 and an overlay portion 38. Screws 39 connect
the front frame member 40 to the left frame member 41 and the right
frame member 42.
[0042] FIG. 4 is a view of the back side (i.e., the side opposite
the front face shown in FIG. 3) of the front frame member 40. FIG.
4 shows a stiffening rib 43.
[0043] As used herein, the expression hook shape includes a shape
which has a body portion, a hook portion and a connecting portion
which connects the body portion and the hook portion, the hook
portion being spaced from the body portion in a first direction,
the hook portion having at least one dimension which is larger in a
transverse direction perpendicular to the first direction than a
corresponding dimension on the connecting portion in the same
transverse direction. As used herein, a statement that a first
structure has a hook shape which is engageable (or engaged) with a
hook shape attached to a second structure means that the respective
hook shapes are shaped such that they can be engaged with each
other so as to prevent the separate structures being from separated
from each other by either or both structures being moved in the
"first" direction (as defined above).
[0044] As used herein, the expression upward hook shape includes a
shape which has an upward hook portion which extends away from a
main surface, the upward hook portion including an upwardly
extending portion and a connecting portion, the connecting portion
connecting the upwardly extending portion to the main surface. For
example, the left side portion 22 of the tile 20 depicted in FIG. 2
has an upward hook shape, as does the left end portion 31 of the
first embodiment of a frame according to the present invention,
depicted in FIG. 3.
[0045] As used herein, the expression downward hook shape includes
a shape which has a downward hook portion which extends away from a
main surface, the downward hook portion including a downwardly
extending portion and a connecting portion, the connecting portion
connecting the downwardly extending portion to the main surface.
For example, the right side portion 21 of the tile 20 depicted in
FIG. 2 has a downward hook shape, as does the right end portion 32
of the first embodiment of a frame according to the present
invention, depicted in FIG. 3.
[0046] When installing a photovoltaic tile as depicted in FIGS. 3
and 4 adjacent to a roofing tile 20 as shown in FIG. 2, the
photovoltaic tile is positioned on the roof such that the right end
portion 32 of the frame of the photovoltaic tile engages with the
left side portion 22 of the first tile, whereby the overlay portion
38 of the frame of the photovoltaic tile is adjacent to or in
contact with the upright portion 25 of the roofing tile, and the
overhang portion 37 of the photovoltaic tile is adjacent to or in
contact with the trough portion 26 of the roofing tile.
[0047] When installing a second photovoltaic tile as depicted in
FIGS. 3 and 4 adjacent to a first photovoltaic tile as depicted in
FIGS. 3 and 4, the second photovoltaic tile is positioned on the
roof such that the right end portion 32 of the frame of the second
photovoltaic tile engages with the left side portion 31 of the
frame of the first photovoltaic tile, whereby the overlay portion
38 of the frame of the second photovoltaic tile is adjacent to or
in contact with the upright portion 35 of the frame of the first
photovoltaic tile, and the overhang portion 37 of the frame of the
second photovoltaic tile is adjacent to or in contact with the
trough portion 36 of the frame of the first photovoltaic tile.
[0048] In FIGS. 5-7, a second embodiment of a frame according to
the present invention is depicted.
[0049] FIG. 5 depicts profiles of a left end portion 51 and a right
end portion 52 of the second embodiment of a frame according to the
present invention, suitable for use in making photovoltaic tiles
which can be used, together with roofing tiles, in constructing a
roof. The left end portion 51 provides an upward hook shape element
which is engaged with a right end portion of a roofing tile 53, and
the right end portion 52 provides a downward hook shape element
which is engaged with a left end portion of a roofing tile 54. The
left end portion 51 and the right end portion 52 depicted in FIG. 5
each include a channel 55, which serves to catch moisture, if any
penetrates between the frame and the photovoltaic element, and
cause the moisture to drain out through the front of the
photovoltaic tile. The right end portion 52 shown in FIG. 5 is
engageable with the left end portion of a second frame having a
profile as shown in FIG. 5.
[0050] FIG. 6 is a profile of a front portion of the second
embodiment of a frame according to the present invention.
[0051] FIG. 7 is a profile of a rear portion of the second
embodiment of a frame according to the present invention. The rear
portion includes holes 71 for receiving screws, nails, bolts or
other connectors which serve to attach the frame to the roof
deck.
[0052] FIG. 8 depicts profiles of a left end portion 81 and a right
end portion 82 of a third second embodiment of a frame according to
the present invention, suitable for use in making photovoltaic
tiles which can be used, together with roofing tiles, in
constructing a roof. The left end portion 81 provides an upward
hook shape element which is engaged with a right end portion of a
roofing tile 83, and the right end portion 82 provides a downward
hook shape element which is engaged with a left end portion of a
roofing tile 84. The left end portion 81 and the right end portion
82 depicted in FIG. 8 each include a channel 85, which serves to
catch moisture, if any penetrates between the frame and the
photovoltaic element, and cause the moisture to drain out through
the front of the photovoltaic tile. The right end portion 82 shown
in FIG. 8 is engageable with the left end portion of a second frame
having a profile as shown in FIG. 8.
[0053] The respective end portions of the frames according to the
present invention can be made of shapes which correspond to the
shapes of the side portions of any suitable roofing tile, a wide
variety of which are known, e.g., various types of "shake" tile,
concrete tile, "S" tiles (e.g., made of terra cotta), W tiles
(e.g., made of terra cotta), etc.
[0054] In a preferred aspect of the present invention, the width of
the frame (i.e., the distance between respective end portions) is a
multiple of the width of the roofing tile to which the end portions
of the frame correspond, so that each photovoltaic element can be
mounted so as to occupy an area which is the same or substantially
the same as the area which would be occupied by a corresponding
number (i.e., equal to the multiple) of roofing tiles, thereby
providing the ability to provide continuity in an overall pattern
of a roof structure which includes roofing tiles and photovoltaic
tiles.
[0055] Preferably, sealant material is applied between the frame
and the photovoltaic element to avoid seepage of water
therebetween. Suitable sealant materials include, e.g., adhesives,
preferably liquid adhesives, such as silicone sealant.
[0056] The present invention is also directed to a method of
constructing a roof using a roofing system according to the present
invention.
[0057] In accordance with the present invention, at least one
photovoltaic tile is laid down on a roof together with a plurality
of roofing tiles. Preferably, a layer of fire barrier roofing
material is secured to the roof deck prior to laying down the tiles
(i.e., the at least one photovoltaic tile and the roofing tiles),
so that the fire barrier roofing material is positioned between the
roof deck and the tiles. Preferably, the layer of fire barrier
roofing material is class C or better, e.g., class C, class B or
class A. In such a case, the fire barrier roofing material
preferably acts as the primary fire barrier and the secondary
weather barrier, while the tiles act as the primary weather
barrier. Any suitable type of barrier roofing material can be
employed, a variety of which are known in the building construction
art, e.g., composite or asphalt shingles.
[0058] In a first embodiment of a method according to the present
invention, a roof deck is attached to a support structure using
nails, screws, bolts or any other suitable attachment members, as
is well known in the building construction art. The support
structure can be any suitable building material, e.g., wood. The
roof deck can likewise be any suitable building material, e.g.,
plywood or OSB.
[0059] In the first embodiment of a method, next, a layer of
composite shingles is applied to the roof deck, as is well known in
the building construction art.
[0060] One or more battens are preferably secured to the roof
before applying the tiles, preferably after applying fire barrier
roofing material to the roof so that the one or more battens (e.g.,
a 1 inch by 2 inch strip of wood) are positioned between the fire
barrier roofing material and the tiles. In such a case, the roofing
tiles and/or the photovoltaic tiles preferably have an anchor
portion (e.g., on which a roofing tile which has a bottom hanging
portion can be engaged) which abuts the batten to serve to assist
in holding the tile in place on the roof.
[0061] In the first embodiment of a method, a plurality of battens
are positioned on the composite shingles and attached to the roof
deck.
[0062] Preferably, at least a first course of roofing tiles are
applied along the bottom edge of the roof, and then a second course
of roofing tiles are applied just above the first course, with a
consistent amount of overlap. A typical roofing tile extends about
17 inches in the direction toward the apex of the roof, and in such
a case, the overlap is preferably from about 3 to about 4 inches.
Providing leeway in the amount of overlap increases the possibility
that a uniform overlap can be applied in the ascending courses of
tiles, such that tiles completely cover the roof and each tile has
approximately the same reveal length (i.e., the exposed area of
each tile has approximately the same dimension in the direction
ascending the slope of the roof). With roofing tiles having a right
side portion which fits into the left side portion of a similar
roofing tile, application of a course of tiles moves from right to
left across the roof.
[0063] Preferably, each course of tiles which includes photovoltaic
tiles includes at least two roofing tiles at both ends of the
course. Preferably, with roofing tiles having a right side portion
which fits into the left side portion of a similar roofing tile,
and corresponding photovoltaic tiles having a right end portion
which fits into the left side portion of a corresponding roofing
tile or into the left end portion of a similar photovoltaic tile,
moving from right to left across the roof, at least two roofing
tiles are applied, then the photovoltaic tiles are applied, and
then at least two more roofing tiles are applied, completing the
course of tiles. However, it should be appreciated that any desired
pattern of roofing tiles and photovoltaic tiles can be made, and
the roofing tiles and photovoltaic tiles can be applied in any
desired sequence.
[0064] Preferably, at least two courses of roofing tiles are
applied adjacent to the apex of the roof. Thus, a preferred pattern
includes a border at least two roofing tiles deep along the outer
periphery of the roof, and the inner region defined by the border
containing or consisting of photovoltaic tiles.
[0065] Preferably, the tiles in each course are offset from the
tiles in the immediately adjacent course or courses. For example, a
first course of tiles is applied, and then the tiles in the second
course of tiles are applied such that the gaps between respective
tiles in the second course are offset from the gaps between
respective tiles in the first course. Preferably, the distance of
the offset is approximately half of the width of the roofing tiles,
i.e., half the length of the edges which are parallel to the bottom
edge of the roofline.
[0066] Preferably, one or more retaining clips for each
photovoltaic tile are attached to the roof deck prior to
positioning such photovoltaic tile on the roof. For example, FIG. 9
shows a retaining clip 90 which is bolted into the roof deck 91
such that the free end of the retaining clip 90 projects over the
roofing tile 92 from the previous course. After all the retaining
clips for the photovoltaic tile 93 have been attached (or the
retaining clip, where only one retaining clip is used for each
photovoltaic tile), the photovoltaic tile 93 is moved into position
on the roof, with the free end of each retaining clip sliding
between the frame of the photovoltaic tile 93 and an underhang
portion 94 (an underhang portion 94 is shown in FIG. 6 also) which
is integral with or rigidly attached to the front portion of the
frame of the photovoltaic tile 93.
[0067] FIG. 9 also shows battens 96 attached to the roof deck
91.
[0068] Preferably, the frame includes a flange portion 95 (a flange
portion 95 is shown in FIG. 6 also) having at least one hole, for
receiving a nail, screw, bolt or other attachment element which
serves to attach the frame to the roof deck.
[0069] After the course of tiles which includes the photovoltaic
tile 93 has been completed, retaining clips 97, for the next course
of tiles, are attached to the roof deck 91. The free end of the
retaining clip 97 projects over the photovoltaic tile 93 from the
previous course. After all the retaining clips for the photovoltaic
tile 98 have been attached, the photovoltaic tile 98 is moved into
position on the roof, with the free ends of the retaining clips
sliding between the frame of the photovoltaic tile 98 and the
underhang portion 99 which is integral with or rigidly attached to
the front portion of the frame of the photovoltaic tile 98.
[0070] In the embodiment shown in FIG. 9, the underhang portion 99
extends parallel to the free end of the retaining clip 97 for a
distance which makes it possible to mount the tile 98 so as to
provide the desired "reveal" (i.e., the exposed area) of the tile
93 below. Preferably, the reveal of each tile is in the range of
from about 13 to about 14 inches. The retaining clip serves, e.g.,
to prevent uplift in windy conditions.
[0071] Preferably, as each photovoltaic tile is positioned, it is
wired such that energy (from the conversion by the photovoltaic
element of light energy into electrical energy) can be collected.
In a preferred aspect of the invention, each photovoltaic tile has
a pair of output wires, and as each photovoltaic tile is installed,
its output wires are connected to collection wires so that the
photovoltaic tiles are connected in series to collection wires. One
end of each of the collection wires preferably extends through the
roof deck and into the interior of the building, e.g., to be
connected to an inverter. Preferably, a structure is provided
whereby the space in the roof deck through which the collection
wires pass is prevented from leaking, e.g., by use of an elbow
structure with a bulkhead, such structures being known in the
art.
[0072] Preferably, the photovoltaic tiles are grounded, e.g., by
using a ground wire which is connected to the respective frames of
each of the photovoltaic elements. In such a case, the photovoltaic
tiles are preferably connected to the ground wire sequentially as
the photovoltaic tiles are installed.
[0073] Preferably, when a photovoltaic tile according to the
present invention is engaged with an adjacent photovoltaic tile or
roofing tile, space is provided which can accommodate expansion and
shrinkage of the frame. For example, FIG. 10 shows a pair of
photovoltaic tiles 101, 102 engaged with each other, in which the
right end portion of the photovoltaic tile 101 is engaged with the
left end portion of the photovoltaic tile 102. As shown in FIG. 10,
space 103 is present between the frames which can accommodate
lateral expansion and contraction of the respective frames. FIG. 10
also shows a right end portion of photovoltaic tile 102 engaged
with a left side portion of a roofing tile 103, and, in a different
course, a roofing tile 104 having a right side portion engaged with
a left side portion of a roofing tile 105. From FIG. 10, it can be
seen that water which enters the space between the roofing tile 104
and the roofing tile 105 will tend to flow along that space (i.e.,
will not escape the trough portion of roofing tile 105 over the
upright portion of the roofing tile 105) until it reaches the lower
end of that course of tiles, and then run out onto the roofing tile
103. Similarly, water which enters the space between the roofing
tile 103 and the photovoltaic tile 102 will tend to flow along that
space (i.e., will not escape the trough portion over the upright
portion of the left side portion of the roofing tile 103) until it
reaches the lower end of that course of tiles, and then run out
onto the tiles in the course below. Similarly, water which enters a
space between a pair of photovoltaic tiles will tend to flow in
that space (i.e., will not escape the trough portion over the
upright portion of the left side portion of the photovoltaic tile).
In such a way, the combination of roofing tiles and photovoltaic
tiles provides an effective primary weather barrier.
[0074] In accordance with one modification of the present
invention, some or all of the end portions of photovoltaic tiles
which are engaged with end portions of other photovoltaic tiles
have shapes which differ from the end portions of photovoltaic
tiles which are engaged with side portions of roofing tiles.
Therefore, where a series of photovoltaic tiles are connected to
one another, it is only the end portions of the photovoltaic tiles
in that series which engage with roofing tiles that need to be
shaped similar to the corresponding end portions of the roofing
tiles. In this modification, three types of photovoltaic tiles are
provided, one type for engaging a photovoltaic tile on its right
end and a roofing tile on its left end, a second type for engaging
a photovoltaic tile on its right end and a photovoltaic tile on its
left end, and a third type for engaging a roofing tile on its right
end and a photovoltaic tile on its left end.
[0075] Preferably, each frame may include one or more drain holes
or notches for the purpose of allowing any moisture which may have
penetrated into the photovoltaic tile to escape and/or to pass
through the frame along the surface of the roof deck.
[0076] Preferably, the photovoltaic tiles are constructed and/or
mounted so as to remain as cool as possible (i.e., to minimize
temperature rise) using any suitable technique, a wide variety of
which are well known to those of skill in the art. For example, one
such technique is to employ conventional counter-battens, i.e., a
first series of battens mounted on the roof deck and running up the
roof deck perpendicular to the roof apex, and a second series of
battens mounted on the first series of battens and perpendicular to
the first series of battens (i.e., parallel to the roof apex), and
then to mount the tiles on the second series of battens.
[0077] Although the photovoltaic tiles, roofing systems and methods
of constructing roofs in accordance with the present invention have
been described in connection with preferred embodiments, it will be
appreciated by those skilled in the art that modifications not
specifically described may be made without departing from the
spirit and scope of the invention defined in the following claims.
For example, any two or more structural parts of the photovoltaic
tiles and/or roofing systems can be integrated; any structural part
of the photovoltaic tiles and/or roofing systems can be provided in
two or more parts (which are held together, if necessary).
* * * * *